THE GRAIL QUEST
Legend says the man who pulls the sword "Excalibur" from the stone, is destined to be king. And so it was that Arthur, a young knight, pulled the sword from the stone and claimed his birthright. But none of the other lords and knights would follow the "boy king" and the land quickly began to wither and die.
At last Arthur turned to Merlin for guidance and advice. Merlin explained that only the Legendary Grail holds the power needed to unite Britain under Arthur's rule. Lost for ages, the grail would heal the rift between the land and the one true king and will bring prosperity to the land and to its people.
So, with aid of his trusted friends Lancelot and Percival, Arthur set forth on his quest to dispel the evil from the land and to reclaim the lost grail.
--From the SNES Knights of the Round instruction manual.